I am really new to postgres. The question looks very simple but I just cant see where I got wrong.
I a table created as follows:
CREATE TABLE IF NOT EXISTS t(
tn VARCHAR(30) NOT NULL,
PRIMARY KEY(tn)
);
I want to insert an instance if the instance does not exist. Here is my code:
INSERT INTO t (tn)
VALUES
(SELECT 'q' WHERE NOT EXISTS (SELECT * FROM t WHERE tn = 'q')) ;
And the psql console keeps giving me the error
ERROR: syntax error at or near "SELECT"
I have checked every piece of code individually, for instance both
SELECT 'q' WHERE NOT EXISTS (SELECT * FROM t WHERE tn = 'q');
and
INSERT INTO t (tn) VALUES ('p');
run without error. But error occurs when I put them together.
Does anyone know where I got wrong..?
Lose VALUES
and the brackets...
INSERT INTO t (tn)
SELECT 'q' WHERE NOT EXISTS (SELECT * FROM t WHERE tn = 'q');
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.